Solver not working properly

On the TI 83 plus the solver function was working fine up until recently. Now I put in the problems and get the error "No sign change" and underneath the answer and boundaries it now says "left-rt=(a different number each time I put in a new equation). I tried resetting my calculator and it didn't fix it.

2 Answers

Clearing the memory usually fixes this problem for me. If you hit 2nd and then + it will take you to the memory menu, where you can clear it by hitting 7. I usually hit clear all memory and confirm, and that fixes the problem for an equation or two, three if I'm lucky. For some reason using the solver too much makes it increasingly inaccurate to the point where you can't get an answer at all, but I don't know why.

no sign change would indicate that the graph of the curve never crosses the x axis, if you graphed the above equation and calculated the zeros, it would come out with -1, 1 which it should, but if you put in x^2+1, the graph would never cross and therefore have no sign change from pos to neg or vice versa, the left-rt are the left and right bounds or the lower and upper bounds which was corrected in later calculators, Please let me know the outcome of graphing both of the above equations and then putting them in the solver. you could also use the quadratic equation to prove the answers if you liked, hope this helps

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Related Questions:

Most probable that you are not using the correct syntax.Press MATH, then scroll down to reach the SOLVER line. Press ENTER. Create the equation, using the ALPHA keyboard to type in letter symbols.Press ENTER. The screen that opens displays the equation and a list of the variable present in your equation. Each letter (variable) must have a value, except the unknown. If there is a 0 after the = sign on the same line as the unknown, you must clear it so as to leave a blank.Specify the lower bound and the upper bound to speed up the search.Once finished press [ALPHA][ENTER] to execute the (SOLVER)

The error data type means that the program is expecting a specific type of data ( number, list, matrix, real, complex, string, etc.) while you are feeding it some other type of data. The point in the program where you are taken when the error occurs is where the exception was launched.

A common source of error stems from the use of variables that are global and defined in some other program. You can use the same name inside your program as long as you declare the variable local. If your program is in fact a function, then all its argument must be passed in the call to the function: You cannot ask a function to read your input.

I will not pretend to know why you get the error, but the few comments I made above may help you debug the program.

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One way is to use the Polynomial Root Finder and Simultaneous Equation Solver app.

Press the APPS key, then select PlySmlt2 and press ENTER. Press ENTER to get past the opening screen, then select "POLY ROOT FINDER" and press ENTER. Select the order of the polynomial and other settings as desired. Press F5 (the GRAPH key) to go to the next screen. Enter the polynomial coefficients, then press F5 to solve. The next screen will show you the roots (unless you selected real roots and the polynomial doesn't have any real roots).

If you don't have the app installed, you can download it fromhttp://education.ti.com/educationportal/sites/US/productDetail/us_poly_83_84.html

Some variable in your function is in archive memory. Press 2ND [MEM] 2 to get into the Memory Management menu. Press 1 to select All. Do you see a variable you're using in your function with an asterisk to its left? If so, navigate down to it and press ENTER to turn off the asterisk. Do this for as many variables as necessary, then press 2ND [QUIT] to exit.